Electromagnetic swing

ABSTRACT

Various embodiments of the present invention are directed to a powered children&#39;s swing. In various embodiments, the swing includes a seat, swing frame, one or more swing arms, a first magnetic component, second magnetic component, swing motion sensor, and swing control circuit. The magnetic components are configured to generate a magnetic force that drives the seat along a swing path. The swing control circuit is configured to control the magnetic components based at least on input from the swing motion sensor and generate control signals causing the seat to swing with a substantially constant amplitude as specified by a user.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/637,326 filed Dec. 14, 2009, which claims priority from provisionalU.S. Application No. 61/121,996 entitled “Solenoid Swing” filed on Dec.12, 2008, and which claims priority from provisional U.S. applicationSer. No. 61/138,286 entitled “Magnet Motor Controller” filed on Dec. 17,2008, each of which is herein incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

Children's swings are typically used to entertain and put to sleepchildren, including infants, by providing a seat that swings smoothlyalong an arcuate path. Powered children's swings are particularlyadvantageous as they are configured to automatically swing a seatwithout the need for a parent or child to continuously provide a motiveforce to keep the seat in motion. Such powered children's swings areknown to be powered in various configurations by motors (e.g., a directcurrent motor) via a mechanical linkage to the swing seat. Other poweredchildren's swings make use of magnetic drive systems, which areadvantageous over motor-driven swings for their superior reliability andquiet operation. For example, certain magnetically driven children'sswings make use of an electromagnet configured to repel a singlepermanent magnet connected to a swing seat, thereby driving the seatalong its arcuate path.

However, current magnetically driven children's swings have a number ofdrawbacks. Current swings are only configured to drive a swing seat withrepulsive magnetic forces. As a result, current magnetic drive systemsare only effective when the swing seat is moving away from one of themagnetic components. This limits the ability of such swings to controlthe dynamics of the swing's motion and provide a smooth and continuousdriving force. In addition, as the magnetic force between two magneticobjects decreases over distance, significant gaps between the magneticdrive components of current swings reduces the power efficiency of theirmagnetic drive systems.

Accordingly, there is a need in the art for a magnetically drivenchildren's swing with an improved magnetic drive system providingimproved swing dynamics and greater power efficiency.

BRIEF SUMMARY OF THE INVENTION

Various embodiments of the present invention are directed to a poweredchildren's swing that includes a magnetic drive system controlled by aswing control circuit and configured to drive the swing's seat such thatthe seat swings with an amplitude specified by a user. According tovarious embodiments, the magnetic drive system is comprised of at leasttwo magnetic components configured to selectively generate a magneticforce which drives the swing seat. In one embodiment, the magnetic drivesystem is an electromagnetic drive system that includes an electromagnetoperatively connected to the swing seat and configured to generate bothattractive and repulsive magnetic forces with another magneticcomponent, thereby driving the swing seat. In another embodiment, themagnetic drive system is a solenoid drive system comprising aelectromagnetic coil and a magnetic component configured to fit withinthe coil and generate a magnetic force that drives the swing seat. Ineach embodiment of the magnetic drive system, the swing control circuitis configured to monitor the amplitude of the seat and generate controlsignals causing the magnetic drive system to drive the swing seat at auser-defined amplitude.

According to various embodiments, the powered children's swing comprisesa seat, swing frame, one or more swing arms, a first magnetic component,a second magnetic component, a swing motion sensor, and a swing controlcircuit. The one or more swing arms are rotatably supported on the swingframe, suspend the seat, and permit the seat to swing along a path. Thefirst magnetic component is operatively connected to the swing frame andthe second magnetic component is operatively connected to the seat. Atleast one of the magnetic components comprises an electromagnet. Theswing motion sensor is configured to generate a signal indicative of anamplitude of the seat's swing motion. The swing control circuit isconfigured to receive the signal from the swing motion sensor, comparethe signal with a goal amplitude for the swing, and generate anelectrical signal based on the comparison that causes electric currentto be supplied to the electromagnet thereby generating an attractivemagnetic force between the first magnetic component and second magneticcomponent that causes the seat to swing with an amplitude nearer to thegoal amplitude.

According to various other embodiments, the powered children's swingcomprises a seat, swing frame, one or more swing arms, a first magneticcomponent, and second magnetic component. The swing frame supports theseat and defines at least one arcuate support member. The one or moreswing arms are rotatably supported on the swing frame and support theseat thereby suspending the seat and permitting the seat to swing alonga path. The arcuate support member is positioned adjacent the swing pathof the seat and is curved generally parallel to the swing path of theseat. The first magnetic component is supported by the arcuate supportmember. The second magnetic component is operatively connected to theseat and is configured to move along a path generally parallel to andadjacent to the arcuate support member as the seat swings along itsswing path. At least one of the magnetic components comprises anelectromagnet configured to selectively generate a magnetic force withthe other magnetic component so as to cause the seat to swing along itsswing path.

According to various other embodiments, a powered children's swingcomprises a seat, swing frame, one or more swing arms, first magneticcomponent, and second magnetic component. The swing frame is configuredto support the seat and defines at least one support member. The one ormore swing arms are rotatably supported on the swing frame and at leastone of the swing arms supports the seat thereby suspending the seat andpermitting the seat to swing along a path. The first magnetic componentis supported by the support member. The second magnetic component isoperatively connected to the seat and comprises an electromagnetic coilhaving a central cavity. The first magnetic component is positionedwithin the central cavity as the second magnetic component passes by thefirst magnetic component. The second magnetic component is configured toselectively generate a magnetic force with the first magnetic componentso as to cause the seat to swing along its swing path.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to the accompanying drawings, which are notnecessarily drawn to scale, and wherein:

FIG. 1 shows a front perspective view of a powered children's swingaccording to one embodiment of the present invention;

FIG. 2A shows a rear perspective view of a powered children's swingaccording to one embodiment of the present invention;

FIG. 2B shows an expanded rear perspective view of the area of a poweredchildren's swing shown in FIG. 2A;

FIG. 3 shows a perspective view of the interior of a component of anelectromagnetic drive system according to one embodiment of the presentinvention;

FIG. 4A shows a schematic section view of an electromagnetic drivesystem according to one embodiment of the present invention;

FIG. 4B shows another schematic section view of an electromagnetic drivesystem according to one embodiment of the present invention;

FIG. 4C shows another schematic section view of an electromagnetic drivesystem according to one embodiment of the present invention;

FIG. 4D shows another schematic section view of an electromagnetic drivesystem according to one embodiment of the present invention;

FIG. 5 shows a schematic section view of an electromagnetic drive systemaccording to one embodiment of the present invention;

FIG. 6 shows a front perspective view of a powered children's swingaccording to one embodiment of the present invention;

FIG. 7A shows a schematic section view of a solenoid drive systemaccording to one embodiment of the present invention;

FIG. 7B shows another schematic section view of a solenoid drive systemaccording to one embodiment of the present invention;

FIG. 7C shows another schematic section view of a solenoid drive systemaccording to one embodiment of the present invention;

FIG. 7D shows another schematic section view of a solenoid drive systemaccording to one embodiment of the present invention;

FIG. 8A shows a front perspective view of components of a poweredchildren's swing according to one embodiment of the present invention;

FIG. 8B shows a rear perspective view of components of a poweredchildren's swing according to one embodiment of the present invention;

FIG. 9 shows a schematic section view of a solenoid drive systemaccording to one embodiment of the present invention; and

FIG. 10 shows a schematic view of the swing control circuit, swingmotion sensor, power supply, and electromagnetic coil of a poweredchildren's swing according to one embodiment.

DETAILED DESCRIPTION OF THE INVENTION

The present invention now will be described more fully hereinafter withreference to the accompanying drawings, in which embodiments of theinvention are shown. This invention may, however, be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein; rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likenumbers refer to like elements throughout.

As described above, various embodiments of the present invention aredirected to a powered children's swing providing a seat that is drivenalong a swing path with controlled amplitude by a magnetic drive system.According to various embodiments, the powered children's swing generallyincludes a swing frame, seat, swing arm, magnetic drive system, powersupply, swing motion sensor, and swing control circuit. As describedabove, in one embodiment, the magnetic drive system is anelectromagnetic drive system. In another embodiment, the magnetic drivesystem is a solenoid drive system. Various embodiments of these drivesystems and their respective control circuits are described herein.

Swing with Electromagnetic Drive System

As shown in FIG. 1, a powered children's swing 100 according to oneembodiment includes a swing frame 120, seat 130, swing arm 140, powersupply 150, electromagnetic drive system, swing motion sensor 180 (shownin FIG. 3), and a swing control circuit 190 (shown in FIG. 2A). Theswing frame 120 includes a base portion 122 and a vertical portion 124.The base portion 122 is configured to rest on a support surface (e.g., afloor) and provide a stable base on which to support the othercomponents of the swing 100. The vertical portion 124 extends upwardlyfrom the base portion 122 forming an elevated arc from which the seat130 is suspended. The vertical portion 124 also includes a supportmember 126 (shown in FIG. 2A) that extends arcuately from one side ofthe vertical portion 124 to an opposite side of the vertical portion124. In addition, the arcuate shape of the support member 126 issubstantially parallel to the swing path of the seat 130. The verticalportion 124 further includes user input controls 128 (e.g., buttons,dials, switches) positioned near the top of the arc formed by thevertical portion 124. As will be described in more detail below inrelation to the swing control circuit 190, the user input controls 128allow the user to control various aspects of the seat's 130 motion(e.g., amplitude), as well as additional features of the swing 100(e.g., timer, sound and music controls).

The seat 130 is configured to support a child or infant and is rotatablyconnected to the vertical portion 124 of the swing frame 120 by a swingarm 140. The swing arm 140 is constructed of a suitably resilientmaterial capable of supporting the weight of the seat 130 and a childoccupying the seat 130. The upper end of the swing arm 140 is connectedto the vertical portion 124 at a pivot point 141. From the pivot point141, the swing arm 140 extends downwardly and curves below the seat 130to one or more connection points. In the illustrated embodiment, theswing arm 140 is connected to a seat frame that directly supports theseat 130. In one embodiment, the seat 130 can be removed from the swingarm 140 by the user as desired. The pivot point 141 permits the swingarm 140 and seat 130 to swing laterally about the pivot point 141 andalong an arcuate swing path (indicated by motion arrows in FIG. 2A). Toprevent the vertical portion 124 of the swing frame 120 from interferingwith the swing path of the seat 130, the bottom portion of the swing arm140 extends forwardly to suspend the seat 130 slightly forward of thevertical portion 124 and pivot point 141.

The swing 100 further includes an electromagnetic drive systemcomprising a first magnetic component and second magnetic componentconfigured to generate a magnetic force that drives the seat 130 alongits swing path. In one embodiment, the first magnetic component ispositioned within the support member 126. The second magnetic componentis positioned within a housing 142 (shown in FIG. 2A and 2B) connectedto the swing arm 140, and is configured to be in close proximity to thefirst magnetic component along at least a portion of the seat's 130swing path.

In the illustrated embodiment of FIG. 2B, the first magnetic componentcomprises a permanent magnet 160 positioned within a medial portion ofthe support member 126, equidistant from the ends of the support member126 and between the seat 130 (shown in FIG. 1) and swing arm 140 (shownin FIG. 1). The permanent magnet 160 is vertically oriented within thesupport member 126 such that one of its poles faces upwards toward thepivot point 141, while the other pole faces downward toward the supportsurface. According to one embodiment, the permanent magnet 160 iscomprised of a ferrous magnet stacked vertically with a neodymiummagnet. In such an embodiment, one of the magnets is secured by aninternal housing within the support member 126 and securely attracts theother magnet, thereby preventing either magnet from moving within thesupport member 126 in response to magnetic forces. According to variousother embodiments, the permanent magnet 160 may be comprised of one ormore other suitable magnets and may be secured within the support member126 in any suitable fashion.

As shown in FIG. 2B, the second magnetic component comprises anelectromagnetic coil 170 positioned within a housing 142. The housing142 is connected to the swing arm 140 such that its upper end 143 ispositioned beneath and adjacent the support member 126. As the swing arm140 rotates about the pivot point 141, the upper end 143 of the housing142 remains adjacent the support member 126. The electromagnetic coil170 is vertically oriented within the housing 142 such that itsuppermost pole is positioned near the upper end 143 of the housing 142.As a result, the uppermost pole of the electromagnetic coil 170 remainsproximate to the support member 126 as the swing arm 140 rotates aboutthe pivot point 141. In addition, the uppermost pole of theelectromagnetic coil 170 is proximate to the lowermost pole of thepermanent magnet 160 as the electromagnetic coil 170 swings by thepermanent magnet 160. According to one embodiment, the electromagneticcoil 170 includes a metal core (e.g., steel, iron), which strengthensthe magnetic force generated by the electromagnetic coil 170. In otherembodiments, however, the electromagnet coil 170 does not include ametal core.

The electromagnetic coil 170 is configured to generate a magnetic forcewith the permanent magnet 160 when supplied with electric current fromthe power supply 150 (shown in FIG. 1). In the illustrated embodiment,the power supply 150 is comprised of one or more batteries (e.g., Dcell, lithium ion, nickel cadmium) positioned within in a batteryhousing connected to the base portion 122 of the swing frame 120.According to various embodiments, the power supply 150 may be anysuitable source of electric current (e.g., a plug-in AC/DC powersupply).

As the direction of the electric current supplied to the electromagneticcoil 170 dictates its polarity, pulses of electric current transmittedto the electromagnetic coil 170 may generate a magnetic force repellingthe electromagnetic coil 170 from the permanent magnet 160 (herein “pushpulses”) or a magnetic force attracting the electromagnetic coil 170 tothe permanent magnet 160 (herein “pull pulses”). As the permanent magnet160 is held in a fixed position within the support member 126 and theelectromagnetic coil 170 is operatively connected to the seat 130, themagnetic forces generated by the magnetic components will drive the seat130 along its swing path. By repeatedly transmitting electric current tothe electromagnetic coil 170 as it passes by the permanent magnet 160,the seat 130 can be continuously driven along its swing path.

As the seat 130 is suspended slightly forward of the pivot point 141,the combined weight of the seat 130 and any load placed on the seat 130(e.g., the weight of a child) creates a torque on the swing arm 140about the pivot point 141 (i.e., a torque oblique to the pivot axis). Asa result, the swing arm 140 flexes slightly downward and toward thevertical portion 124 of the swing frame 120. To optimize the powerefficiency of the electromagnetic drive system, the swing arm 140 isconfigured to flex toward a target position in response to a targetload. In some embodiments, the permanent magnet 160 and electromagneticcoil 170 are axially aligned when in the target position, allowing thelowermost pole of the permanent magnet 160 and uppermost pole of theelectromagnetic coil 170 to be in close proximity one another. Forexample, in embodiments of the swing 100 specifically designed toaccommodate infant children, the target load may be equal to the weightof an infant child (e.g., 10 pounds). Accordingly, when an infantweighing 10 pounds is placed in the seat 130, the swing arm 140 willflex into the target position. Likewise, in embodiments designed toaccommodate a wider range of children, the target load may be the weightof an average child (e.g., 20 pounds). Although the electromagneticdrive system is configured to drive the seat 130 under any loadingcondition within the swing's design tolerances (e.g., when no child ispositioned in the seat, or when a heavy child is positioned in theseat), the electromagnetic drive system operates more efficiently whenthe swing arm 140 is flexed to the target position.

In addition, the swing 100 is able to reduce the power needed to drivethe seat 130 by applying the magnetic force generated by theelectromagnetic coil 170 to the lower end of the swing arm 140. As theelectromagnetic coil 170 is positioned at the bottom of the swing arm140, a significant distance from the pivot point 141, the swing arm 140has a high degree of leverage on the pivot point 141. This allows theelectromagnetic drive system to generate the torque necessary to drivethe seat 130 with less power than a drive system having less mechanicalleverage.

As will be described in more detail below, the amplitude of the seat's130 swinging motion is controlled by the swing control circuit 190,which is configured to control the timing, direction, and width ofelectric current supplied to the electromagnet coil 170 based on input(e.g., a signal) from the swing motion sensor 180 (shown in FIG. 3).According to various embodiments, the swing motion sensor 180 isconfigured to sense a characteristic of the seat's 130 motion andgenerate a signal indicative of the seat's 130 amplitude. For example,in the illustrated embodiment, the swing motion sensor 180 is configuredto sense the velocity of the seat 130 at a target sensing point alongits swing path and generate a signal indicating the sensed velocity(e.g., a signal having a time width corresponding to the velocity of theseat 130 as it passes the sensing point). As the amplitude of the seat's130 motion correlates to the seat's 130 velocity, the signal generatedby the swing motion sensor 180 is indicative of the seat's amplitude. Aswill be appreciated by one of skill in the art, the amplitude indicativesignal generated by the swing motion sensor 180 may be representative ofspeed or velocity. In other embodiments, the swing motion sensor 180 isconfigured to sense when the seat 130 changes direction (e.g., at thepeak of the seat's 130 swing path). For example, signals correspondingto the time elapsed between changes in the seat's 130 direction, orsignals corresponding to the arc-length traveled between changes in theseat's 130 direction, would be also be indicative of the seat's 130amplitude.

As shown in the illustrated embodiment of FIG. 3, the swing motionsensor 180 is comprised of an infrared sensor 181, a first reflectivesurface 182, and a second reflective surface 183. The infrared sensor181 and first reflective surface 182 are configured to generate avelocity indicative signal, while the infrared sensor 181 and secondreflective surface 183 are configured to generate a direction indicativesignal. The infrared sensor 181 is positioned adjacent theelectromagnetic coil 170 on the upper end 143 of the housing 142. Assuch, the infrared sensor 181 is continuously adjacent the supportmember 126 as the seat 130 (not shown) moves along its swing path. Thefirst reflective surface 182 is positioned adjacent the permanent magnet160 on the lower-side of the support member 126 such that, when theswing arm 140 is positioned equidistant from the ends of the supportmember 126, the first reflective surface 182 is directly above andadjacent the infrared sensor 181. As will be described in more detailbelow in relation to the swing control circuit 190, the velocity of theseat 130 as it passes by the center of the support member 126 (i.e., thevelocity sensing point) may be determined by measuring the width of thesignal generated by the infrared sensor 181 as it senses the reflectionof the first reflective surface 182.

Although not necessary for the control of certain embodiments, thesecond reflective surface 183 permits the swing control circuit 190 todetermine the direction in which the seat 130 is traveling. The secondreflective surface 183 is positioned proximate to the first reflectivesurface 182 on the lower-side of the support member 126 such that thevelocity of the seat 130 is substantially the same as the infraredsensor 181 passes by the first reflective surface 182 and the secondreflective surface 183. In addition, the second reflective surface 183has a width differing from the width of the first reflective surface182. Accordingly, the swing control circuit 190 is able to differentiatebetween signals corresponding to the first reflective surface 182 andsignals corresponding to the second reflective surface 183. Bydetermining which signal is received first for a pair of signalscorresponding to the reflective surfaces 182, 183, the swing controlcircuit 190 determines the direction the seat 130 is traveling as itpasses by the center of the support member 126.

According to another embodiment (not shown), the swing motion sensor iscomprised of an optical sensor (e.g., a computer mouse sensor)configured to sense the movement of a target, such as a wheel or wheelsection, operatively connected to swing arm 140 (e.g., at the pivotpoint 181). In such an embodiment, the swing motion sensor 180 is ableto sense the movement of the seat 130 by detecting the movement of thewheel. The wheel may also include one or more cut-out sections toprovide a reference point for the swing control circuit 190. Forexample, in one embodiment, the reference point indicates the positionof the swing arm 140. This embodiment of swing motion sensor 180 isadvantageous in that it is capable of providing the absolute positionand velocity of the seat 130 at any point along the seat's 130 swingpath.

In addition, according to various other embodiments, the swing motionsensor 180 may be a Hall effect sensor, laser sensor, accelerometer,light interrupter, or other sensor suitable of generating a signalindicative of an amplitude of the seat's 130 motion and, if necessary,indicating the direction of the seat's 130 motion. According to yetanother embodiment, the swing motion sensor may be comprised of multiplesensors configured to indicate the position, velocity, and/or directionof the seat 130 at one or more points along the seat's 130 swing path.

Swing Amplitude Control with Electromagnetic Drive System

According to various embodiments, the swing control circuit 190comprises an integrated circuit configured to receive signals from theuser input controls 128 and swing motion sensor 180, and generatecontrol signals to control the amplitude of the seat's 130 motion. FIG.10 shows a schematic diagram of one embodiment of the swing controlcircuit 190, including its internal memory and comparator and theconnections between swing control circuit 190 and the swing motionsensor 180, electromagnetic coil 170, and power supply 150. In theillustrated embodiment of FIG. 1, the swing control circuit 190 ispositioned proximate to the user input controls 128 within a housingsituated at the top of the arc formed by the vertical portion 124 of theswing frame 120. As described briefly above, the control signalsgenerated by the swing control circuit 190 are configured to control thetiming, direction, and width of electric current transmitted from thepower supply 150 to the electromagnet coil 170. Based on input from theswing motion sensor 180 and the user input controls 128, the swingcontrol circuit 190 is configured to generate control signals causingthe swing 130 to swing with an amplitude desired by the user.

In controlling the swing 100, the swing control circuit 190 firstreceives one or more control signals from one or more of the user inputcontrols 128 indicating a target amplitude for the seat's 130 motion. Inthe illustrated embodiment, a user may select from six pre-definedamplitude settings via the user input controls 128. For example, in oneembodiment, the first setting indicates the user would like the seat's130 amplitude to remain between 9 and 10 degrees, where zero degrees isperpendicular to the support surface. The remaining five settingscorrespond to incrementally higher amplitude ranges (e.g., 14-15°,17-18°, 22-23°, 26-27.5°, and 29.5-30.5°). When the user selects one ofthe pre-defined amplitude settings via the user controls 128, the swingcontrol circuit 190 sets the corresponding amplitude range as the targetamplitude. In addition, the user input controls 128 provide a manualamplitude setting, which allows the user to physically move the seat 130to a desired amplitude and release the seat 130. When the swing controlcircuit 190 detects that the user has selected the manual amplitudesetting, the swing control circuit 190 determines the amplitude of theseat 130 at the point it is released by the user and sets the determinedamplitude as the target amplitude. The user input controls 128 alsoprovide the user with the option of selecting a swing time defining howlong the seat 130 will be driven at the target amplitude (e.g., 10minutes).

Based on the control signals received from the user input controls 128,the swing control circuit 190 determines a target amplitude and, ifspecified, a swing time. Next, the swing control circuit 190 determinesa target velocity corresponding to the target amplitude. The targetvelocity represents the velocity with which the seat 130 will pass bythe swing motion sensor's 180 velocity sensing point when the seat 130is swinging with an amplitude equal to the target amplitude. In oneembodiment, the swing control circuit 190 retrieves the target velocityfrom a look-up table indicating target velocities for various ranges ofamplitudes. In another embodiment, the swing control circuit 190calculates the target velocity based on the target amplitude. In yetanother embodiment, the control signal generated by the user inputcontrols 128 is configured to directly indicate a programmed targetvelocity corresponding to the amplitude selected by the user.

After determining the target velocity, the swing control circuit 190waits to receive a first signal from the swing motion sensor 180. In theillustrated embodiment, the user moves the seat 130 away from itsresting point and release the seat 130 such that the seat 130 swingspast the velocity sensing point of the swing motion sensor 180 (i.e.,the center of the support member 126). The initial direction the seat130 travels after being released by the user will be referred to hereinas the “first direction.” As the electromagnetic coil 170 swings pastthe velocity sensing point in the first direction, the swing controlcircuit receives 190 two initial signals from the swing motion sensor180. As described above, one of the initial signals corresponds to thefirst reflective surface 182 (herein the “velocity signal”), while theother corresponds to the second reflective surface 183 (herein the“direction signal”).

Based on the initial velocity signal, the swing control circuit 190 nextdetermines the initial velocity of the seat 130. As described above inrelation to the illustrated embodiment of FIG. 3, the velocity signalindicates that the infrared sensor 181 senses the presence of the firstreflective surface 182. The resulting velocity signal has a leadingedge, indicating the infrared sensor 181 is positioned beneath the firstreflective surface 182, and a trailing edge, indicating the infraredsensor 181 is no longer beneath the first reflective surface 182. Bymeasuring the time elapsed between the leading edge and trailing edge ofthe velocity signal, the swing control circuit 190 determines the widthof the signal (e.g., in milliseconds). As the infrared sensor 181 movespast the first reflective surface 182 with the same velocity as the seat130, the width of the velocity signal is inversely proportional to thevelocity of the seat 130. Accordingly, the swing control circuit 190determines the velocity of the seat 130 (e.g., in units of meters persecond) as it passes by the velocity sensing point by dividing the widthof the first reflective surface 182 (e.g., in millimeters) by the widthof the velocity signal received from the swing motion sensor 180. Inanother embodiment, the target velocity corresponds to a desiredvelocity signal width and the swing control circuit 190 is configured tocompare the width of the velocity signal to the target velocity width,rather than calculating the actual velocity of the seat 130.

Next, the swing control circuit 190 compares the initial velocity of theseat 130 to the target velocity to determine the width of the firstpulse of electric current transmitted to the electromagnetic coil 170(i.e., the “current pulse width”). If the initial velocity of the seat130 is less than the target velocity, the swing control circuit 190 setsthe current pulse width to a programmed initial pulse width (e.g., 16milliseconds). If the initial velocity of the seat 130 is greater thanthe target velocity, the swing control circuit 190 sets the next pulsewidth to zero, or “no pulse.” As mentioned briefly above, in anotherembodiment, the swing control circuit 190 compares the width of thevelocity signal to a target velocity width. Among other advantages, thismethod allows for the swing control circuit 190 to compensate for areduction in the magnitude of the voltage provided by the power supply150 (e.g., as a result of low batteries).

After passing by the velocity sensing point, the seat 130 swings upwardsin the first direction, reaches its peak amplitude, and begins to swingdownwards in the second direction toward the permanent magnet 160. Theswing control circuit 190 waits to receive the next velocity signal fromthe swing motion sensor 180. Immediately after the velocity signal isreceived, the swing control circuit 190 generates a control signalcausing a push pulse to be transmitted to the electromagnetic coil 170having a pulse width equal to the determined current pulse width. FIG.4A shows the position and polarity of the electromagnetic coil 170 andpermanent magnet 160 as the first push pulse is transmitted. Inaddition, FIGS. 4A-4B indicate the orientation of the poles of thepermanent magnet 160 and electromagnetic coil 170 according to oneembodiment; “N” being a north pole and “S” being a south pole.

The first push pulse is transmitted at the trailing edge of the velocitysignal. In other words, once the infrared sensor 181 has swung past thefirst reflective surface 182, current is transmitted to theelectromagnetic coil 170. At the point when this occurs, the uppermostpole of the electromagnet coil 170 is slightly off-center from thelowermost pole of the permanent magnet 160 in the direction of theseat's 130 motion (as shown in FIG. 4A). As a result, when theelectromagnetic coil 170 receives the push pulse, it is repelled awayfrom the permanent magnet 160 in the direction of the seat's 130 motion,thereby driving the seat 130 along its swing path.

According to certain embodiments, the push pulse described above istransmitted following a programmed firing delay after the trailing edgeof the velocity signal. Testing of various embodiments of theelectromagnetic drive system has shown that such a delay can improve theefficiency of the system, requiring less power to maintain the desiredamplitude of the seat 130. In one embodiment, the programmed firingdelay is determined by the swing control circuit 190 from a look-uptable that correlates firing delays to swing velocity, with lower swingvelocities corresponding to longer firing delays. For example, if theswing control circuit 190 determines the appropriate firing delay is 10milliseconds, the swing control circuit 190 will transmit the push pulseto the electromagnetic coil 170 10 milliseconds after the trailing edgeof the velocity signal from the swing motion sensor 180. In addition,the programmed firing delay corresponds to the distance theelectromagnetic coil 170 is from the permanent magnet 160. Accordingly,the firing delay may be programmed to ensure push pulses are transmittedwhen the electromagnetic coil 170 is a certain distance from thepermanent magnet 160. In another embodiment, the firing delay may beprogrammed to occur an amount of time after the leading edge of thevelocity signal.

According to another embodiment, the firing delay described above may beimplemented by using additional position indicating reflective strips toindicate the position of the electromagnetic coil 170. For example, theswing motion sensor 180 may include one or more additional reflectivestrips positioned along the support member 126 in order to indicate atarget location or locations in which the swing control circuit 190should trigger the electromagnetic coil 170. In such embodiments, theswing control circuit 190 is configured to distinguish between theadditional reflective strips and trigger push or pull pulses to theelectromagnetic coil 170 based on the position of the electromagneticcoil 170 as indicated by the additional reflective strips. According toyet another embodiment, the swing motion sensor 180 comprises a sensorcapable sensing the absolute position of the electromagnetic coil 170(e.g., an optical mouse sensor) in relation to the permanent magnet 160,while the swing control circuit 190 is configured to trigger theelectromagnetic coil 170 at certain positions as indicated by the swingmotion sensor 180.

Just prior to the push pulse being transmitted, the swing controlcircuit 190 receives the most recent velocity signal and stores thewidth of the velocity signal. Using the method described above, theswing control circuit 190 determines the current velocity of the seat130. If the current velocity is lower than the target velocity, theswing control circuit 190 increases the new current pulse width by adefined increment. For example, in one embodiment, the swing controlcircuit 190 increases the current pulse width by 8 milliseconds when thecurrent velocity is determined to be lower than the target velocity,with a maximum pulse width of 200 milliseconds. Likewise, if the currentvelocity is greater than the target velocity, the swing control circuit190 decreases the current pulse width by a defined increment. Forexample, in one embodiment, the swing control circuit 190 decreases thecurrent pulse width by 8 milliseconds anytime the current velocity isgreater than the target velocity, with the pulse width being zeroanytime the current pulse width is calculated to be less than 16milliseconds. According to one embodiment, the swing control circuit 190is configured to compare the velocity of the seat 130 to the targetvelocity and adjust the pulse width every half-cycle (i.e., every timethe seat 130 passes the velocity sensing point). According to otherembodiments, the swing control circuit 190 may be configured to adjustthe pulse width less frequently (e.g., every other half-cycle or everythird half-cycle).

After being propelled in the second direction by the first push pulse,the seat 130 swings upwards until reaching its peak amplitude. As theseat 130 swings back in the first direction and approaches the permanentmagnet 160, the swing control circuit 190 generates a control signalcausing a pull pulse to be transmitted to the electromagnetic coil 170with a pulse width equal to the determined current pulse width. FIG. 4Bshows the position and polarity of the electromagnetic coil 170 as thefirst pull pulse is transmitted.

As illustrated in FIG. 4B, the swing control circuit 190 transmits thepull pulse when the electromagnetic coil 170 is a slight distance awayfrom the permanent magnet 160. The swing control circuit 190 isconfigured to predict when the electromagnetic coil 170 will be in thedesired position by first determining the elapsed time between theprevious two velocity signals. The elapsed time between the signalsrepresents the duration of the most recently completed half-period ofthe seat's 130 motion. The swing control circuit 190 then subtracts aprogrammed amount of time (corresponding to the distance theelectromagnetic coil 170 will be from the permanent magnet 160 when thepull pulse is transmitted) from the half-period duration and determinesa trigger time for triggering the pull pulse. In one embodiment, thesubtracted time is determined according to a look-up table associatingsubtraction times with seat velocities or half-period durations. Forexample, if the determined trigger time is 2.8 seconds, the swingcontrol circuit 190 will trigger the pull pulse to the electromagneticcoil 170 2.8 seconds after the trailing edge of the preceding velocitysignal. According to other embodiments in which the swing motion sensor180 is configured to indicate when the electromagnetic coil 170 ispositioned in a target location, the swing control circuit 190 isconfigured to trigger the pull pulse to the electromagnetic coil 170when the swing motion sensor indicates the electromagnetic coil 170 isin the target pull-pulse location.

As shown in FIG. 4B, the pull pulse drives the seat 130 along its swingpath in the first direction. After the electromagnetic coil 170 passesby the velocity sensing point, a push pulse having the same pulse widthas the pull pulse (i.e., the current pulse width) is transmitted to theelectromagnetic coil 170. As shown in FIG. 4C, the position and polarityof the electromagnetic coil 170 relative to the permanent magnet 160 issubstantially similar to its position in FIG. 4A. After the push pulseis transmitted, the process described above for determining the currentpulse width for the following pair of pull and push pulses is repeated.FIG. 4D shows the position and polarity of the electromagnetic coil 170as the seat 130 swings back toward the permanent magnet 160 in thesecond direction and the next pull pulse is triggered.

The swing control circuit 190 is further configured to account for theeffects varying support surfaces and changes to the seat's 130 center ofgravity may have on the control of the swing 100. For example, in theillustrated embodiment, the swing motion sensor 180 is configured tosense the velocity of the seat 130 at the center of its swing path(i.e., the target sensing point), which occurs at the center of thesupport member 126 under ideal conditions. In other words, under idealconditions, the target sensing point and the velocity sensing point arethe same. However, if the swing 100 is positioned on a support surfacethat is not substantially perpendicular to the direction of gravity, theswing path of the seat 130 will shift relative to the velocity sensingpoint such that the velocity sensing point will be offset from thetarget sensing point (the center of the swing path). Similarly, as achild shifts its weight within the seat 130, the center of gravity ofthe seat 130 may affect the position of the swing path relative to thevelocity sensing point. In either of these situations, the velocitysensed by the swing motion sensor 180 will be lower than the velocity ofthe seat 130 at the true center of its swing path. If this error is notaccounted for, the swing control circuit 190 will control the seat 130as if it is swinging slower than it actually is, resulting in anundesirably high amplitude.

After the seat 130 has completed one full period of motion, the swingcontrol circuit 190 begins checking for changes in the position of thevelocity sensing point of the swing motion sensor 180 relative to theseat's 130 swing path. When the swing motion sensor 180 is sensing thevelocity of the seat 130 at the center of the swing path (the targetsensing point), the amount of time the seat 130 is positioned on eitherside of the first reflective surface 182 is substantially the same.Accordingly, by comparing the amount of time the seat 130 is positionedon either side of the first reflective surface 182, the swing controlcircuit 190 determines if the swing motion sensor 180 is measuring thevelocity of the seat at an offset point. For example, if for one periodof motion the swing control circuit 190 determines that the seat 130 ispositioned on a first side of the first reflective surface 182 for agreater amount of time than it is on a second side of the firstreflective surface 182, the swing control circuit 190 determines thatthe swing motion sensor 180 is sensing the velocity of the swing at anoffset point.

According to another embodiment, the swing control circuit 190determines whether the swing motion sensor 180 is sensing the velocityof the swing at an offset point by comparing the percentage of timeduring one sample period of the seat's 130 motion the seat 130 was oneither side of the velocity sensing point to a target percentage. Thismethod is useful for embodiments of the swing 100 in which the targetsensing point is not the center of the swing path. For example, in suchembodiments, the seat 130 will be positioned on either side of thevelocity sensing point for different amounts of time depending on theseat's 130 amplitude, even when the velocity sensing point is in thesame position as the target sensing point. However, when the velocitysensing point is in the same position as the target sensing point, thepercentage of time the seat 130 is on either side of the velocitysensing point (i.e., the target percentage) will remain substantiallyconstant regardless of the swing's amplitude. Accordingly, by comparingtimed percentages to the target percentage, the swing control circuit190 can determine any offset of the velocity sensing point.

To compensate for errors resulting from an offset velocity sensingpoint, the swing control circuit 190 is configured to adjust the sensedvelocity in proportion to the detected offset. For example, in oneembodiment, the swing control circuit 190 is configured to calculate thedifference between the swing times and determine a corrective factor bywhich to adjust the sensed velocity based on the calculated timedifference (e.g., via an algorithm or look-up table). By estimating thevelocity at the center point of the seat's 130 swing path based on theoffset-velocity sensed by the swing motion sensor 180, the swing controlcircuit 190 is able to accurately drive the seat 130 at the targetamplitude.

In addition, the swing control circuit 190 is configured to time futurepull pulses based on the determined offset. For example, if the swingpath of the seat 130 is shifted relative to the first reflective surface182, it is also true that the electromagnetic coil 170 will not pass bythe permanent magnet 160 at the center of its swing path. Accordingly,the swing control circuit 190 is configured to increase or decrease thetriggering time for transmitting pull pulses in proportion to thedetermined offset. This ensures the pull pulses are being transmittedwhen the electromagnetic coil 170 is in the proper position relative tothe permanent magnet 160.

According to various embodiments, the swing control circuit 190 isconfigured to repeat the processes described above in order to continuedriving the seat 130 at the user specified amplitude until the swingtime specified by the user has elapsed or the user otherwise stops theswing (e.g., by hand or via the user input controls). In addition,various aspects of the operation of the swing control circuit 190 maybemodified according to various embodiments. For example, in certainembodiments the swing control circuit 190 is configured to control theelectromagnetic drive system such that only pull pulses are used todrive the seat 130. In other embodiments, the swing control circuit 190is configured to control the electromagnetic drive system such that onlypush pulses are used to drive the seat 130. Moreover, the swing controlcircuit 190 may be configured to operate based on a variety of differentcontrol signals (e.g., the various amplitude-indicative signalsdescribed above).

Alternative Embodiments of Swing with Electromagnetic Drive System

According to various other embodiments of the claimed invention, apowered children's swing may include variations of the electromagneticdrive system and other features described above in relation to theembodiments shown in FIGS. 1-4. For example, the electromagnetic drivesystem according to various embodiments includes at least one magnet ormagnetic material and at least one electromagnet capable of selectivelyattracting or repelling the magnet or magnetic material. In oneembodiment, the first magnetic component positioned within the supportmember 126 is a magnetic material (e.g., Iron). In other embodiments,the first magnetic component is an electromagnetic coil positionedwithin the support member 126, while the second magnetic component is apermanent magnet or magnetic material positioned within the housing 142.In yet another embodiment, both the first and second magnetic componentsare electromagnetic coils positioned within the support member 126 andhousing 142, respectively.

According to various embodiments, the positioning and orientation ofcertain swing components may also be modified. For example, in oneembodiment the first magnetic component is positioned within the supportmember 126 at an off-center location (e.g., a position not equidistantfrom the ends of the support member 126). In addition, the first andsecond magnetic components may be oriented vertically or horizontallywithin the support member 126 and housing 142. In certain embodiments,the second magnetic component and its housing may be positioned adjacenta side edge or upper edge of the support member 126 (as opposed to beingadjacent the lower edge as shown in FIG. 1). In another embodiment,housing 142, support member 126, and magnetic components may bepositioned nearer to the pivot point 141 and concealed within a drivehousing.

In other embodiments, the first magnetic component may be comprised ofmultiple magnets or magnetic material members. For example, in theembodiment shown in FIG. 5, the first magnetic component is comprised oftwo arrays of permanent magnets 560 spaced apart within the supportmember 126. As in the embodiment shown in FIGS. 1-3, the electromagneticcoil 170 is operatively connected to the swing arm 140. The permanentmagnets 560 are secured within the support member 526 by spacers 527(positioned between the permanent magnets 560) and compressed springs528 (positioned on either end of the support member 126). In theillustrated embodiment, the permanent magnets 560 and electromagneticcoil 170 are oriented perpendicular to the support member 126.

The illustrated embodiment includes the swing control circuit 190 (notshown), which is configured to intermittently generate a control signalcausing push pulses to be transmitted to the electromagnetic coil 170 asit passes by each of the permanent magnets 560. In one embodiment, theswing control circuit 190 utilizes an optical sensor (e.g., the computermouse sensor described above) to detect the position of theelectromagnetic coil 170 in relation to the permanent magnets 560 andtrigger push pulses to the electromagnetic coil 170 at the appropriatepoints. In another embodiment, separate sensors are positioned along thesupport member 126 and configured to indicate the position of each ofthe permanent magnets 560 to the swing control circuit 190, which isconfigured to trigger push pulses accordingly. In yet anotherembodiment, the swing control circuit 190 may be configured to transmitpush pulses to the electromagnetic coil 170 based on a timing algorithmcorresponding to the position of the permanent magnets 560. By causingthe electromagnetic coil 170 to be repelled from the permanent magnets560 over a broader range of the seat's swing path, the drivingefficiency and control of the seat's motion may be improved. In variousother embodiments utilizing multiple permanent magnets, the swingcontrol circuit 190 may be configured to generate push and/or pullpulses to drive the seat 130.

As will also be appreciated by one of skill in the art, the generalprinciples of the electromagnetic drive system described above may beincorporated into various other swing embodiments. For example, thecomponents of the swing 100 described above may be modified to permitthe electromagnetic drive system to drive the seat 130 forward andbackward, as opposed to laterally. In addition, it is contemplated thatthe embodiments of the swing control circuit may be modified toaccommodate various embodiments of the electromagnetic drive system suchthat the amplitude of the swing seat may be controlled as describedabove.

Swing with Solenoid Drive System

As shown in FIG. 6, a powered children's swing 600 according to oneembodiment includes a swing frame 620, seat 630, swing arms 640,solenoid drive system, swing motion sensor 680, and swing controlcircuit 690. As used herein, the term “solenoid” refers to a type ofelectromagnet comprising an electromagnetic coil configured to wraparound a movable core (e.g., a permanent magnet). The swing frame 620includes two A-frame portions 622 positioned on either side of the seat630. The A-frame portions 622 are each formed from two legs connectedtogether at their upper ends and configured to rest on a support surface(e.g., a floor) at their lower ends. Each A-frame portion 622 alsoincludes a support member 626 that extends arcuately from a medialportion of one A-frame leg to a medial portion of the adjoining A-frameleg. The arcuate shape of the support member 626 is substantiallyparallel to the swing path of the seat 630. In addition, the swing frame620 includes user input controls (not shown), which allow the user tocontrol various aspects of the seat's 630 motion. In one embodiment, theuser input controls are substantially similar to those described abovein relation to the swing 100 shown in FIG. 1.

The seat 630 is configured to support a child or infant and is pivotallyconnected to the A-frame portions 622 by the swing arms 640 positionedon either side of the seat 630. The upper end of each swing arm 640 isconnected to its respective A-frame portion 622 at a pivot point 641positioned near the vertex of each pair of A-frame legs. From the pivotpoints 641, the swing arms 640 extend downwardly toward the supportmembers 626. The swing arms 640 are operatively connected to the seat630, thereby suspending the seat 630 above the support surface. Thepivot points 641 permit the swing arms 640 and the seat 630 to swingforward and backward about the pivot point 641 and along an arcuateswing path (indicated by motion arrows in FIG. 6).

The swing 600 further includes a solenoid drive system comprising afirst magnetic component and second magnetic component configured togenerate a magnetic force that drives the seat 630 along its swing path.In the illustrated embodiment, the first magnetic component is apermanent magnet 660 (shown in FIGS. 7A-7D) positioned within thesupport member 626. The second magnetic component comprises anelectromagnetic coil 670 operatively connected to a lower end of theswing arm 640. According to various embodiments, the first and secondmagnetic components of the solenoid drive system may be positioned onboth sides of the seat 630 or positioned on only one side of the seat630. For the purposes of the description of the solenoid drive systemherein, the components will be described as being positioned on one sideof the seat 630.

As shown in the illustrated embodiment of FIGS. 7A-7D, the permanentmagnet 660 is positioned within a medial portion of the support member626, equidistant from the ends of the support member 626. According tovarious embodiments, the permanent magnet 660 has a width (measuredalong the length of the support member 626) equal to or greater than thewidth of the electromagnetic coil 670. According to one embodiment, thepermanent magnet 660 is horizontally oriented within the support member626 such that one of its poles faces forward toward the front of theswing 600, while the other pole faces rearward toward the rear of theswing 600. The poles of both the permanent magnet 660 andelectromagnetic coil 670 according to one embodiment are indicated by“N” (north) and “S” (south) in FIGS. 7A-7D. As described above inrelation to the permanent magnet 160 shown in FIG. 2B, the permanentmagnet 660 may be comprised of one or more suitable magnets and may besecured within the support member 626 in any suitable fashion. Forexample, in one embodiment, the permanent magnet 660 is comprised ofseveral smaller, connected permanent magnets arranged in an arcuateshape substantially parallel to the curvature of the support member 626.Moreover, according to various embodiments of the present invention(including but not limited to the swings 100, 600), one or both of thefirst and second magnetic components may have a substantially arcuateshape.

As shown in FIGS. 6 and FIGS. 7A-7D, the electromagnetic coil 670 doesnot include a metal core and is positioned such that it fits around thesupport member 626. As a result, a portion of the support member 626remains positioned within the cavity of the electromagnetic coil 670 andsubstantially concentric with the electromagnetic coil 670 as the swingarm 640 rotates about the pivot point 641. In addition, as theelectromagnetic coil 670 swings past the center of the support member626, the permanent magnet 660 passes through the cavity of theelectromagnetic coil 670.

The electromagnetic coil 670 is configured to generate a magnetic forcewith the permanent magnet 660 when supplied with electric current fromthe power supply 650. As described above in relation to the power supply150, the power supply 650 may comprise any suitable source of electriccurrent (e.g., batteries, plug-in AC/DC power supply). Similar to theelectromagnetic drive system described above, pulses of electric currenttransmitted to the electromagnetic coil 670 by the power supply 650 maybe used to drive the seat 630 along its swing path. However, thesolenoid drive system allows the seat 630 to be driven by the reactionof the permanent magnet 660 to the concentrated magnetic field presentwithin the cavity of the electromagnetic coil 670. As a result, themagnetic force generated by the pulses is exceptionally strong. Inaddition, by applying the magnetic force generated by magneticcomponents to the end of the swing arm 640, the system reduces the forcenecessary to drive the seat 630. These properties of the solenoid drivesystem increase the overall efficiency of the system by requiring lesspower to drive the seat 630 along its swing path.

As will be described in more detail below, the amplitude of the seat's630 swinging motion can be controlled by the swing control circuit 690,which is configured to control the timing, direction, and width ofelectric current supplied to the electromagnetic coil 670 based on inputfrom the swing motion sensor 680. In the illustrated embodiment of FIG.6, the swing motion sensor 680 is an optical sensor (e.g., computermouse sensor) positioned near the pivot point 641. The swing motionsensor 680 is configured to generate a velocity signal indicative of thevelocity of the seat 630 as it passes by the center of the supportmember 626 (i.e., the velocity sensing point), as well as a directionsignal indicating the direction in which the seat 630 is traveling. Inanother embodiment, the swing motion sensor 680 of FIG. 6 is furtherconfigured to generate a signal indicating the absolute position of theelectromagnetic coil 670 in relation to the permanent magnet 680.

According to various other embodiments, the swing motion sensor 680 maybe a sensor capable of generating a signal indicative of the seat's 630amplitude and determining the direction in which the seat 630 istraveling (e.g., Hall effect sensor, laser sensor, light interrupter,accelerometer). As described above, a signal corresponding to thevelocity of the seat 630 or indicating when the seat 630 changesdirection may be indicative of the seat's 630 amplitude. As will bedescribed in more detail below, certain embodiments of the swing 600include a swing motion sensor capable of determining the position of theseat 630 (e.g., various embodiments of the swing motion sensor 180described above).

Swing Amplitude Control with Solenoid Drive System

According to various embodiments, the swing control circuit 690comprises an integrated circuit configured to receive signals from theuser input controls and swing motion sensor 680, and generate controlsignals to control the amplitude of the seat 630. In the illustratedembodiment of FIG. 6, the swing control circuit 690 is positioned withinthe swing frame 620, near the pivot point 641. Based on input from theswing motion sensor 680 and the user input controls, the swing controlcircuit 690 is configured to generate control signals causing the seat630 to swing with an amplitude desired by the user.

In controlling the swing 600, the swing control circuit 690 firstreceives one or more control signals from one or more of the user inputcontrols. As described above in relation to the swing control circuit190, the swing control circuit 690 first determines a target amplitudeand, if specified, a swing time based on the control signals receivedfrom the user input controls. Next, the swing control circuit 690determines the target velocity corresponding to the target amplitude. Inone embodiment, this may also be accomplished using the methodologydescribed above in relation to the swing control circuit 190.

After determining the target velocity, the swing control circuit 690waits to receive a first velocity signal from the swing motion sensor680. Similarly to the swing 100, the user first moves the seat 630 awayfrom its resting point and release the seat 630 such that theelectromagnetic coil 670 swings past the sensing point of the swingmotion sensor 680. As the electromagnetic coil 670 swings past thevelocity sensing point in a first direction, the swing control circuit690 receives an initial velocity signal and an initial direction signalfrom the swing motion sensor 680.

Based on the initial velocity signal, the swing control circuit 690 nextdetermines the initial velocity of the seat 630. In one embodiment, thismay be accomplished using one of the methodologies described above inrelation to the swing control circuit 190. Next, the swing controlcircuit 690 compares the initial velocity of the seat 630 to the targetvelocity to determine the width of the first pulse of electric currenttransmitted to the electromagnetic coil 670 (i.e., the “current pulsewidth”). In one embodiment, the current pulse width is determined basedon the same starting pulse (16 milliseconds) and incremental pulseincreases and decreases described above in the relation to the swingcontrol circuit 190.

After passing by the velocity sensing point, the seat 630 swings upwardsin the first direction, reaches its peak amplitude, and begins to swingdownwards in the second direction toward the permanent magnet 660. Asthe electromagnetic coil 670 approaches the permanent magnet 660 in thesecond direction, the swing control circuit 690 waits to receive thenext velocity signal from the swing motion sensor 680. When the swingcontrol circuit 690 detects the trailing edge of the velocity signal,the swing control circuit 690 generates a control signal causing a pushpulse having a pulse width equal to the current pulse width to betransmitted to the electromagnetic coil 670. FIG. 7A shows the positionand polarity of the electromagnetic coil 670 and permanent magnet 660 asthe first push pulse is transmitted. As can be seen from FIG. 7A, thepush pulse occurs just as the leading pole of the electromagnetic coil670 moves past the end of the permanent magnet 660. According to variousother embodiments, the push pulses generated by the solenoid drivesystem may also incorporate the firing delay described above in relationto the swing control circuit 190. In addition, according to variousembodiments, the swing control circuit 690 may be configured to triggerthe push pulse using a number of different methods, such as thosedescribed herein in relation to the swing control circuit 190.

After receiving the velocity signal and triggering the push pulse, theswing control circuit 690 determines the new current pulse width bycomparing the current velocity of the seat 630 with the target velocity.The swing control circuit 690 also prepares to trigger a pull pulse bydetermining the appropriate trigger time. In one embodiment, both ofthese functions are accomplished in accordance with the methodologiesdescribed above in relation to the swing control circuit 190.

After being propelled in the second direction by the first push pulse,the seat 630 swings upwards, reaches its peak amplitude, and swings backin the first direction toward the permanent magnet 660. When the triggertime determined above elapses, the swing control circuit 690 generates acontrol signal causing a pull pulse having a pulse width equal to thedetermined next pulse width to be transmitted to the electromagneticcoil 670. FIG. 7B shows the position and polarity of the electromagneticcoil 670 as the first pull pulse is transmitted. As illustrated in FIG.7B, the trigger time results in the swing control circuit 690 triggeringthe pull pulse when the electromagnetic coil 670 is a slight distanceaway from the permanent magnet 660. In addition, the polarity of theelectromagnetic coil 670 is reversed in order to attract theelectromagnetic coil 170 to the permanent magnet 660. However, asdescribed above in relation to the swing control circuit 190, a maximumpulse width defined by the swing control circuit 690 limits the width ofthe pull pulse and ensures that the pull pulse ends before theelectromagnetic coil 670 becomes aligned with the permanent magnet 660.In addition, according to various embodiments, the swing control circuit690 may be configured to trigger the pull pulse using a number ofdifferent methods, such as those described herein in relation to theswing control circuit 190.

As shown in FIG. 7B, the pull pulse drives the seat 630 along its swingpath in the first direction. After the electromagnetic coil 670 passesby the velocity sensing point, the swing control circuit 690 generates acontrol signal causing a push pulse having a pulse width equal to thewidth of the pull pulse (i.e., the current pulse width) to betransmitted to the electromagnetic coil 670. As shown in FIG. 7C, theposition and polarity of the electromagnetic coil 670 relative to thepermanent magnet 660 is substantially similar to its position andpolarity in FIG. 7A.

After the push pulse of FIG. 7C is transmitted, the process describedabove for determining the new current pulse width for the next pair ofpull and push pulses is repeated. For example, FIG. 7D shows theposition and polarity of the electromagnetic coil 670 as the seat 630swings back toward the permanent magnet 660 in the second direction. Inaddition, using the methodology described above in relation to the swingcontrol circuit 190, the swing control circuit 690 is also configured toadjust the velocity indicated by the swing motion sensor 680 tocompensate for any detected offset velocity sensing point (e.g., as aresult of an uneven support surface, or changes in the seat's 630 centerof gravity). The swing control circuit 690 is also configured to adjustthe trigger time for pull pulses in order to compensate for an offsetvelocity sensing point.

According to various embodiments, the swing control circuit 690 isconfigured to repeat the processes described above in order to continuedriving the seat 630 at the user specified amplitude until the swingtime specified by the user has elapsed or the user otherwise stops theswing (e.g., by hand or via the user input controls). In addition,various aspects of the operation of the swing control circuit 690 may bemodified according to various embodiments. For example, in certainembodiments the swing control circuit 690 is configured control thesolenoid drive system such that only push pulses are used to drive theseat 130. Moreover, the swing control circuit 690 may be configured tooperate based on a variety of different control signals (e.g., thevarious amplitude-indicative signals described above).

Alternative Embodiments of Swing with Solenoid Drive System

According to various other embodiments of the claimed invention, apowered children's swing may include variations of the solenoid drivesystem and other features described above in relation to the embodimentsshown in FIGS. 6-7D. For example, according to certain embodiments, theconfiguration of the swing frame 620 may be altered. In one embodiment,the support member 626 and magnetic components may be positioned nearerto the pivot point 641 and concealed within a drive housing.

In another embodiment, shown in FIGS. 8A and 8B, the solenoid drivesystem is incorporated on a swing frame 820 resembling the swing frame120 described above.

Similarly to the swing frame 120, the swing frame 820 is configured topermit a swing arm 840 to swing laterally about a pivot point 841. Inthe illustrated embodiment, the solenoid drive system comprising anelectromagnetic coil 870 and a permanent magnet (not shown) isconfigured to drive the seat (not shown) laterally along a swing path.Similarly to the solenoid drive system described above, theelectromagnetic coil 870 is positioned around a support member 826 andconfigured to drive the seat via a drive arm 899 operatively connectedto the swing arm 840.

According to various other embodiments, the first magnetic component ofthe swing 600 may comprise multiple permanent magnets. For example, inthe embodiment shown in FIG. 9, the first magnetic component iscomprised of two arrays of permanent magnets 960 spaced apart within thesupport member 626. The permanent magnets 960 are secured within thesupport member 626 by spacers 927 positioned between the permanentmagnets 960 and compressed springs 928 positioned on either end of thesupport member 926. According to one embodiment, the polarity of thepermanent magnets 960, indicated by “N” (north) and “S” (south)markings, are mirrored such that the magnet arrays repel each other.

In the illustrated embodiment, the swing control circuit 690 (not shown)is configured to drive the seat 630 (not shown) by pulsing theelectromagnetic coil 670 as it moves along the support member 626between the permanent magnets 960 arrays. Based on signals received fromthe swing motion sensor 680 (not shown), the swing control circuit 690determines the direction of the electromagnetic coil 670 and reversesits polarity as its amplitude peaks and swing direction changes. In theembodiment shown in FIGS. 7A-7D and described above, the electromagneticcoil 670 is pulsed at a particular time coinciding with its positionrelative to the permanent magnet 660. However, in the illustratedembodiment of FIG. 9, the electromagnetic coil 670 may be pulsed anddriven by the magnetic forces generated between it and the permanentmagnets 960 across the full range of the electromagnetic coil's 670motion. For example, in one embodiment, the swing motion sensor 680 is asensor configured to sense the absolute position of the electromagneticcoil 170 (e.g., an optical mouse sensor) and map the motion of theelectromagnetic coil 170, as well as the seat 630, to a processor of theswing control circuit 190. The swing control circuit 690 is thenconfigured to pulse the electromagnetic coil 670 at appropriate pointsover the range of the electromagnetic coil's 670 motion based on theposition of the electromagnetic coil 670 as indicated by the swingmotion sensor 680.

By keeping the polarity of the electromagnetic coil 670 configured todrive the electromagnetic coil 670 in the direction of the seat's 630motion, the swing control circuit 690 can pulse the electromagnetic coil670 as needed to maintain the amplitude of the seat's 630 motion.Accordingly, the swing control circuit 690 is configured to monitor theamplitude of the seat 630 as described above in relation to the swing600 (e.g., by comparing the velocity of the seat 630 to a targetvelocity or sensing the absolute position of the seat 630) and generatecontrol signals triggering pulses to the electromagnetic coil 670 asnecessary to maintain the target amplitude. In certain embodiments, theswing control circuit 690 is configured to self-start, or begin swingingthe seat 630 without a motive force provided by the user. This isaccomplished by transmitting pulses of electric current in alternatingdirections to the electromagnetic coil 670, thereby causing theelectromagnetic coil 670 (and thereby the seat 630) to be pulled backand forth between the permanent magnet 960 arrays.

As will be appreciated by one of skill in the art, various otherembodiments of a power children's swing incorporating the solenoid drivesystem described herein may be used to drive a swing seat at auser-defined, substantially constant amplitude.

CONCLUSION

Many modifications and other embodiments of the present invention willcome to mind to one skilled in the art to which this invention pertainshaving the benefit of the teachings presented in the foregoingdescriptions and the associated drawings. Therefore, it is to beunderstood that the invention is not to be limited to the specificembodiments disclosed and that modifications and other embodiments areintended to be included within the scope of the appended claims.Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation.

What is claimed is:
 1. A method for controlling a swing comprising aseat driven along a swing path by an electromagnetic drive systemincluding a first magnetic component and a second magnetic component,wherein at least one of the first and second magnetic componentscomprises an electromagnet and wherein the method comprises the stepsof: sensing an amplitude of the seat's motion along the swing path;comparing the sensed amplitude with a value indicative of a goalamplitude for the swing; generating an attractive magnetic force betweenthe first magnetic component and second magnetic component that causesthe seat to swing with an amplitude nearer to the goal amplitude; andgenerating a repulsive magnetic force between the first magneticcomponent and second magnetic component that causes the seat to swingwith an amplitude nearer to the goal amplitude.
 2. The method of claim1, further comprising the steps of: determining when the second magneticcomponent is a certain distance from the first magnetic component;determining when the second magnetic component is moving toward thefirst magnetic component; and generating the attractive magnetic forcewhen the second magnetic component is the certain distance from thefirst magnetic component and the second magnetic component is movingtoward the first magnetic component.
 3. The method of claim 1, furthercomprising the steps of: determining the position of the first magneticcomponent in relation to a center point of the seat's swing path; andtiming the generation of the attractive magnetic force based, at leastin part, on the position of the first magnetic component in relation tothe center point.
 4. The method of claim 1, further comprising the stepsof: determining when the second magnetic component is a certain distancefrom the first magnetic component; determining when the second magneticcomponent is moving away from the first magnetic component; andgenerating the repulsive magnetic force when the second magneticcomponent is the certain distance from the first magnetic component andthe second magnetic component is moving away from the first magneticcomponent.
 5. The method of claim 1, wherein the step of generating theattractive magnetic force comprises generating a first electrical signalbased on the comparison that causes electric current to be supplied tothe electromagnet thereby generating an attractive magnetic forcebetween the first magnetic component and second magnetic component; andwherein the step of generating the repulsive magnetic force comprisesgenerating a second electrical signal based on the comparison thatcauses electric current to be supplied to the electromagnet therebygenerating a repulsive magnetic force between the first magneticcomponent and second magnetic component.
 6. The method of claim 5,wherein the first electrical signal and second electrical signalcorrespond to a duration of electric current transmitted to theelectromagnet.
 7. The method of claim 1, wherein the attractive magneticforce and repulsive magnetic force are generated in the same half-periodof the seat's motion.
 8. The method of claim 1, further comprisingrepeating the steps of sensing the amplitude of the seat's motion,comparing the sensed amplitude with the value indicative of the goalamplitude, generating the attractive magnetic force, and generating therepulsive magnetic force in order to drive the seat along the swing pathwith a substantially constant amplitude that is substantially equal tothe goal amplitude.
 9. A method for controlling a swing comprising aseat driven along a swing path by an electromagnetic drive systemincluding a first magnetic component and a second magnetic component,wherein at least one of the first and second magnetic componentscomprises an electromagnet and wherein the method comprises the stepsof: sensing an amplitude of the seat's motion along the swing path;comparing the sensed amplitude with a value indicative of a goalamplitude for the swing; determining when the second magnetic componentis a certain distance from the first magnetic component; determiningwhen the second magnetic component is moving away from the firstmagnetic component; and generating a magnetic force between the firstmagnetic component and second magnetic component when the secondmagnetic component is the certain distance from the first magneticcomponent and the second magnetic component is moving away from thefirst magnetic component, the magnetic force causing the seat to swingwith an amplitude nearer to the goal amplitude.
 10. The method of claim9, wherein the step of generating the magnetic force comprisesgenerating an electrical signal based on the comparison that causeselectric current to be supplied to the electromagnet thereby generatinga magnetic force between the first magnetic component and secondmagnetic component.
 11. The method of claim 10, wherein the electricalsignal corresponds to a duration of electric current transmitted to theelectromagnet.
 12. The method of claim 9, wherein the magnetic forcecomprises a repulsive magnetic force.
 13. The method of claim 9, furthercomprising repeating the steps of sensing the amplitude of the seat'smotion, comparing the sensed amplitude with the value indicative of thegoal amplitude, determining when the second magnetic component is thecertain distance from the first magnetic component, determining when thesecond magnetic component is moving away from the first magneticcomponent, and generating the magnetic force in order to drive the seatalong the swing path with a substantially constant amplitude that issubstantially equal to the goal amplitude.
 14. A method for controllinga swing comprising a seat driven along a swing path by a drive system,the method comprising the steps of: displacing and releasing the seat,thereby causing the seat the swing along the swing path; sensing a firstamplitude of the seat's motion along the swing path, the first amplitudeof the seat's swing motion occurring at a first point in time andresulting from the displacement of the seat; sensing a second amplitudeof the seat's motion along the swing path, the second amplitude of theseat's swing motion occurring at a second point in time, wherein thesecond point in time occurs after the first point in time; comparing thefirst sensed amplitude with the second sensed amplitude; and driving theseat via the drive system to swing with an amplitude nearer to the firstamplitude.
 15. The method of claim 14, wherein the step of displacingand releasing the seat comprises manually grasping a portion of theswing, moving the seat away from its resting point, and releasing theseat such it begins to swing along the motion path.
 16. The method ofclaim 14, wherein the step of driving the seat via the drive systemcomprises generating an electrical signal that causes the drive systemto drive the seat to swing with an amplitude nearer to the firstamplitude.